This is a very valid point. Players have to improve as their careers progress and one-year rentals must be major contributors. I don't like being a team whose success is highly dependent on freshmen.
IMO, the loss of Hunter has really thrown a monkey wrench into being able to predict our success. We know Rob is already a pretty good PG who will be around for a while. If Jerome is as good as we have been led to believe, I'd feel a lot more confident about the future (not that I'm pessimistic about it as is). The problem is we just don't know, unfortunately. The same goes for Race as well. Forrester and Anderson are more typical freshmen who need experience before we can have an idea of what they might be capable of.
Thus far the sophomores and juniors just haven't shown that they are going to be long-term answers. I think a few can be, but they really need to show it.